TY - JOUR T1 - A Transformational Approach to Negation in Logic Programming JF - J. Log. Program. Y1 - 1990 A1 - Roberto Barbuti A1 - Paolo Mancarella A1 - Dino Pedreschi A1 - Franco Turini VL - 8 ER - TY - CONF T1 - Intensional Negation of Logic Programs: Examples and Implementation Techniques T2 - TAPSOFT, Vol.2 Y1 - 1987 A1 - Roberto Barbuti A1 - Paolo Mancarella A1 - Dino Pedreschi A1 - Franco Turini JF - TAPSOFT, Vol.2 ER -